Improved Algorithm to Trace Boundary Curves on Two-Dimensional Square Meshes

2020 ◽  
Vol 14 (5) ◽  
pp. 816-823
Author(s):  
Masatomo Inui ◽  
◽  
Munekazu Kawano ◽  
Issei Watanabe ◽  
Nobuyuki Umezu
Keyword(s):  
Computation Time ◽  
Boundary Curve ◽  
Minkowski Sum ◽  
Two Dimensional ◽  
Marching Cubes ◽  
Cross Sectional ◽  
Cutter Path ◽  
Classification Pattern ◽  
Curve Tracing ◽  
Mold Part

In the contoured cutter path computation of a mold part, the Minkowski sum shape of the mold part CAD model and an inverted cutter model is sliced by a horizontal plane at a specific height. The cutter path can be obtained by tracing the boundary curve of the cross-sectional figure in the two-dimensional (2D) square mesh model. In the boundary curve tracing of the square mesh, the 2D marching cubes method based on the classification of the cell pattern of the mesh is typically used. We extended the classification pattern so that the existence of very small shapes in the cell, which is ignored by the conventional 2D marching cubes method, is evaluated in tracing the boundary curve. By using this technology, a robust and accurate contoured cutter path can be obtained without any increase in the computation time.

scholarly journals Three-dimensional Capsular Volume Measurements in Multidirectional Shoulder Instability

2018 ◽  
Vol 21 (3) ◽  
pp. 134-137
Author(s):  
Yong Cheol Jun ◽  
Young Lae Moon ◽  
Moustafa I Elsayed ◽  
Jae Hwan Lim ◽  
Dong Hyuk Cha
Keyword(s):  
Rotator Cuff ◽  
Surface Area ◽  
Three Dimensional ◽  
Volume Measurement ◽  
Control Group ◽  
Two Dimensional ◽  
Cross Sectional ◽  
Volume Measurements ◽  
Glenoid Surface ◽  
3D Software

BACKGROUND: In a previous study undertaken to quantify capsular volume in rotator cuff interval or axillary pouch, significant differences were found between controls and patients with instability. However, the results obtained were derived from two-dimensional cross sectional areas. In our study, we sought correlation between three-dimensional (3D) capsular volumes, as measured by magnetic resonance arthrography (MRA), and multidirectional instability (MDI) of the shoulder.METHODS: The MRAs of 21 patients with MDI of the shoulder and 16 control cases with no instability were retrospectively reviewed. Capsular areas determined by MRA were translated into 3D volumes using 3D software Mimics ver. 16 (Materilise, Leuven, Belgium), and glenoid surface area was measured in axial and coronal MRA views. Then, the ratio between capsular volume and glenoid surface area was calculated, and evaluated with control group.RESULTS: The ratio between 3D capsular volume and glenoid surface area was significantly increased in the MDI group (3.59 ± 0.83 cm³/cm²) compared to the control group (2.53 ± 0.62 cm³/cm²) (p < 0.01).CONCLUSIONS: From these results, we could support that capsular volume enlargement play an important role in MDI of the shoulder using volume measurement.

scholarly journals Swarm v2: highly-scalable and high-resolution amplicon clustering

2015 ◽  
Author(s):  
Frédéric Mahé ◽  
Torbjørn Rognes ◽  
Christopher Quince ◽  
Colomban de Vargas ◽  
Micah S Dunthorn
Keyword(s):  
High Resolution ◽  
Initial Phase ◽  
Computation Time ◽  
Two Dimensional ◽  
Fine Scale ◽  
Single Linkage ◽  
Fasta Format ◽  
Operational Taxonomic Units ◽  
Abundant Otus ◽  
Local Clustering

Previously we presented Swarm v1, a novel and open source amplicon clustering program that produced fine-scale molecular operational taxonomic units (OTUs), free of arbitrary global clustering thresholds and input-order dependency. Swarm v1 worked with an initial phase that used iterative single-linkage with a local clustering threshold (d), followed by a phase that used the internal abundance structures of clusters to break chained OTUs. Here we present Swarm v2 that has two important novel features: 1) a new algorithm for d = 1 that allows the computation time of the program to scale linearly with increasing amounts of data; and 2) the new fastidious option that reduces under-grouping by grafting low abundant OTUs (e.g., singletons and doubletons) onto larger ones. Swarm v2 also directly integrates the clustering and breaking phases, dereplicates sequencing reads with d = 0, outputs OTU representatives in fasta format, and plots individual OTUs as two-dimensional networks.

Abstract 273: New Reconstruction Technique for MRA to “Fly Through” the Lumen of the Cerebral Vasculature

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Mallikarjunarao Kasam ◽  
Siva S Ketha ◽  
Soumya Konduru
Keyword(s):  
Virtual Endoscopy ◽  
Statistical Parameter ◽  
Computation Time ◽  
Reconstruction Technique ◽  
Cross Sectional ◽  
Root Area ◽  
Contrast Enhanced ◽  
3.0 T ◽  
Area Product ◽  
Sectional Structure

Methods Patient exams were performed under an IRB-approved protocol. Two 3D SWIRLS [3] single phase contrast-enhanced angiographies with 1mm3 spatial resolution were used for this work. Clinical exams were acquired on 3.0 T scanners (GE, DVMR 20.1IB, Milwaukee, WI). Data analysis The angiogram was post-processed using tree analysis and virtual endoscopy modules of Analyze 11.0 software (Analyze 11.0; Biomedical Imaging Resource, Mayo Clinic, Rochester, MN) to fly through the artery. A statistical parameter called Brightness Area Product (BAP) was defined as the sum of the intensities above the sample minimum intensity/threshold set by the user. Results and Discussions Figures (I-IV) show the methodology to fly through the part of anterior carotid artery (ACA) and all statistics of part of the artery (Fig. IV) with angles from the “Root” to its different branches of A1 to G2 (Fig. III). Figure II shows the snap shot of the fly through/internal cross sectional structure of ACA of branch “E2”, at the location marked as “red dot”. Table (IV) represents different statistics including length, angle from the root, area of cross section and the BAP of the branches mentioned in Fig. III. The computation time for this method is < 5 minutes compared to the other reconstruction techniques (>~30 minutes). We proposed a simple and fast automated post-processing method to fly through the artery using Analyze 11.0 software. This technique can be extended to any arteries to monitor internal vasculature and to estimate the stenosis using the statistical parameter BAP, which generates a master profile/database of arteries. References 1 Shu Y, Bernstein MA, ISMRM 2009 p764.

scholarly journals An evaluation of ultrasonic arrays for the static and dynamic measurement of wheel–rail contact pressure and area

2020 ◽  
Vol 234 (10) ◽  
pp. 1580-1593
Author(s):  
Henry Brunskill ◽  
Andy Hunter ◽  
Lu Zhou ◽  
Rob Dwyer Joyce ◽  
Roger Lewis
Keyword(s):  
Contact Pressure ◽  
Ultrasonic Transducer ◽  
Dynamic Contact ◽  
Pressure Profile ◽  
Calibration Procedure ◽  
Railway Vehicle ◽  
Profile Measurement ◽  
Two Dimensional ◽  
Cross Sectional ◽  
Contact Conditions

The interfacial contact conditions between a railway vehicle wheel and the rail are paramount to the lifespan, safety and smooth operation of any rail network. The wheel–rail interface contact pressure and area conditions have been estimated, calculated and simulated by industry and academia for many years, but a method of accurately measuring dynamic contact conditions has yet to be realised. Methods using pressure-sensitive films and controlled air flow have been employed, but both are limited. Ultrasonic reflectometry is the term given to active ultrasonics in which an ultrasonic transducer is mounted on the outer surface of a component and a sound wave is generated. This ultrasonic wave packet propagates through the host medium and reflects off the contacting interface of interest. The reflected waveform is then detected and contact area and interfacial stiffness information can be extracted from the signal using the quasi-static spring model. Stiffness can be related to contact pressure by performing a simple calibration procedure. Previous contact pressure measurement work has relied on using a focusing transducer and a two-dimensional scanning arrangement which results in a high-resolution image of the wheel–rail contact, but is limited to static loading of a specimen cut from a wheel and rail. The work described in this paper has assessed the feasibility of measuring a dynamic wheel–rail contact patch using an array of 64 ultrasonic elements mounted in the rail. Each element is individually pulsed in sequence to build up a linear cross-sectional pressure profile measurement of the interface. These cross-sectional, line measurements are then processed and collated resulting in a two-dimensional contact pressure profile. Measurements have been taken at different speeds and loads.

Investigation of the Early Soot Formation Process in a Transient Spray Flame Via Spectral Measurements of Laser-Induced Emissions

2006 ◽  
Vol 7 (2) ◽  
pp. 93-101 ◽  
Author(s):  
T Aizawa ◽  
H Kosaka
Keyword(s):  
Formation Process ◽  
Soot Formation ◽  
Yttrium Aluminium Garnet ◽  
Two Dimensional ◽  
Spectral Measurements ◽  
Cross Sectional ◽  
Soot Particles ◽  
Nozzle Orifice ◽  
Spray Flame ◽  
Soot Precursors

In order to investigate the early soot formation process in a diesel spray flame, two-dimensional imaging and spectral measurements of laser-induced emission from soot precursors and soot particles in a transient spray flame achieved in a rapid compression machine (2.8 MPa, 710 K) were conducted. The 3rd harmonic (355 nm) and 4th harmonic (266 nm) Nd: YAG (neodymium-doped yttrium aluminium garnet) laser pulses were used as the light source for laser-induced fluorescence (LIF) from soot precursors and laser-induced incandescence (LII) from soot particles in the spray flame. The two-dimensional imaging covered an area between 30 and 55 mm downstream from the nozzle orifice. The results of two-dimensional imaging showed that strong laser-induced emission excited at 266 nm appears only on the laser incident side of the spray flame, in contrast to an entire cross-sectional distribution of the emission excited at 355 nm, indicating that 266 nm-excited emitters are stronger absorbers and more abundant than 355 nm-excited emitters in the spray flame. The spectral measurements were conducted at three different positions, 35, 45, and 55 mm downstream from the nozzle orifice, along the central axis of the spray, where LIF from soot precursors was observed in a previous two-dimensional imaging study. The spectra measured in upstream positions showed that broad emission peaked at around 400–500 nm, which is attributable to LIF from polycyclic aromatic hydrocarbons (PAHs). The spectra measured in downstream positions appeared very much like grey-body emission from soot particles.

A Comparison Between Three- and Two-Dimensional Thermal Finite Element Analysis of the Gas Metal Arc Welding Process

2003 ◽  
Author(s):  
Mohammad S. Davoud ◽  
Xiaomin Deng
Keyword(s):  
Finite Element ◽  
3D Model ◽  
Gas Metal Arc Welding ◽  
Welding Process ◽  
Element Model ◽  
Transient Temperature ◽  
Two Dimensional ◽  
Element Analysis ◽  
Cross Sectional ◽  
2D Model

Predictions of transient temperature distributions in welding can help the selection of welding process parameters that minimize residual stresses. A three-dimensional (3D) thermal finite element model of bead-on-plate gas metal are welding (GMAW) is presented and is used to evaluate a cross-sectional, two-dimensional (2D) counterpart model. While the thermomechanical problem of welding is 3D in nature, it is shown that the 2D model can provide temperature field predictions comparable to those of the 3D model, even though the 2D model tends to predict peak temperatures higher than those of the 3D model. Both types of model predictions are compared to welding test measurements.

The stability of pendent liquid drops. Part 1. Drops formed in a narrow gap

1973 ◽  
Vol 59 (4) ◽  
pp. 753-767 ◽  
Author(s):  
E. Pitts
Keyword(s):  
Contact Angles ◽  
Two Dimensional ◽  
Narrow Gap ◽  
Cross Sectional ◽  
Liquid Drops ◽  
Maximum Area ◽  
Area Increase ◽  
Equilibrium Profiles ◽  
The Stability ◽  
Horizontal Support

We consider a drop of liquid hanging from a horizontal support and sandwiched between two vertical plates separated by a very narrow gap. Equilibrium profiles of such ‘two-dimensional’ drops were calculated by Neumann (1894) for the case when the angle of contact between the liquid and the horizontal support is zero. This paper gives the equilibrium profiles for other contact angles and the criterion for their stability. Neumann showed that, as the drop height increases, its cross-sectional area increases until a maximum is reached. Thereafter, as the height increases, the equilibrium area decreases. This behaviour is shown to be typical of all contact angles. When the maximum area is reached, the total energy is a minimum. It is shown that the drops are stable as long as the height and the area increase together.

scholarly journals Structural and Functional Changes in Maternal Heart during Pregnancy: An Echocardiographic Study

2017 ◽  
Vol 02 (04) ◽  
pp. 072-076
Author(s):  
Sunanda Kasula ◽  
Sumalatha Beeram ◽  
Ramakrishna Janapati ◽  
Indrani Garre
Keyword(s):  
Blood Pressure ◽  
Gestational Age ◽  
Systolic Function ◽  
Interventricular Septum ◽  
Clinical History ◽  
Left Ventricular ◽  
Two Dimensional ◽  
Cross Sectional ◽  
Functional Changes ◽  
Significant Difference

Abstract Background Pregnancy is associated with profound physiologic alterations in the maternal cardiovascular system. This study aimed to investigate maternal cardiac performance during normal pregnancy by two-dimensional echocardiography parameters and various functional and structural alterations. Methods This was a cross-sectional study of 100 normal pregnant women who attended the antenatal clinic, and all participants had clinical history, physical examination, and 12-lead electrocardiogram. Two-dimensional, M-mode, and Doppler echocardiography was done. Echocardiographic parameters were compared with normal age-matched controls from previously published studies. Results The mean age of the study group was 23.35 ± 3.05 years, mean systolic blood pressure was 110.5 ± 8.69 mm Hg, and mean diastolic blood pressure was 71.6 ± 6.77 mm Hg. There was an increase in left atrial (LA) diameter, left ventricular end diastolic diameter, and interventricular septum (IVS) thickness as gestational age advanced. There was a gradual decrease in E-wave velocity, and E/A ratio increased during the second trimester and decreased during the third trimester. The E-wave deceleration time increased with gestational age There was no statistically significant difference between IVS thickness and E/A ratio (p = 1.000). Conclusion Cardiac chamber dimensions, LV wall thickness, and LA size, most indices of systolic function although within normal range, were significantly higher in pregnant Asian Indian women than in the controls. This study shows that the subtle reduction in myocardial compliance appears as an adaptive response to changes of preload, afterload, and LV geometry.

Sign in / Sign up

Export Citation Format

Share Document